I'm wondering how to mention about geisha and prostitution. Wikipedia vigorously denied that geisha has anything to do with prostitution, while the author of the famous book Memoirs of a Geisha is not so positive.
Q: Here's a question you've undoubtedly heard before: Are geisha prostitutes? A: As a matter of fact, all through the years I worked on this novel, that was the first question people asked me. The answer isn't a simple yes or no. The so-called "hot springs geisha," who often entertain at resorts, are certainly prostitutes. But as Sayuri says in the novel, you have to look at how well they play the shamisen, and how much they know about tea ceremony, before you determine whether they ought properly to call themselves geisha. However, even in the geisha districts of Kyoto and Tokyo and other large cities, a certain amount of prostitution does exist. For example, all apprentice geisha go through something they call mizuage, which we might call, "deflowering." It amounts to the sale of their virginity to the highest bidder. Back in the '30s and '40s, girls went through it as young as thirteen or fourteen--certainly no later than eighteen. It's misleading not to call this prostitution, even child prostitution. So we can't say that geisha aren't prostitutes. On the other hand, after her mizuage, a first-class geisha won't make herself available to men on a nightly basis. She'll be a failure as a geisha, though, if she doesn't have a man who acts as her patron and pays her expenses. He'll keep her in an elegant style, and in exchange she'll make herself sexually available to him exclusively. Is this prostitution? Not in the exact sense we mean it in the West, where prostitutes turn "tricks" with "johns," and so on. To my mind, a first-class geisha is more analogous to a kept mistress in our culture than to a prostitute.-- source